With amazing research now suggesting that Beijing swifts, the tiny creatures most residents pass by without noticing, are some of the most well-travelled birds on the planet, averaging an astonishing 124,000 miles of flight in their life, barely landing for years-on-end, and migrating as far as the southern tip of Africa. this week on Sinica hosts Kaiser Kuo and Jeremy Goldkorn invited Terry Townshend, founder of the environmental education organization Eco-Action and author of Birding Beijing for an inside look at how the scientific community discovered these amazing facts, and then more generally for a discussion of how the changing urban landscape in Beijing is affecting the natural environment for these amazing creatures.